To prepare a cosmetic capable of simultaneously performing cleaning and conditioning of a keratinous material.

The subject deterging and conditioning cosmetic composition contains, in a cosmetically acceptable medium, at least one anionic surfactant, at least one amphoteric surfactant and at least one selected water-insoluble carboxylate, wherein the total number of carbon atoms in the carboxylate is ≤27 if it contains no unsaturation and ≤50 if it contains at least one unsaturation, the ester concentration is >1 % and the ratio of the anionic surfactant to the amphoteric surfactant is ≤3. The composition is useful for hair and skin cleaning and care.